17 October 2007 - An international
team of scientists from ten nations returns
today from a six-week voyage studying Antarctic
sea ice, bringing with them fresh insights
into whether climate change is affecting
the ice and ecosystems of the Southern Ocean.
An extensive science program led jointly
by the Antarctic Climate & Ecosystems
Cooperative Research Centre (ACE CRC) and
the Australian Antarctic Division, has gathered
valuable information that will help develop
more accurate global climate models and
will also help us understand how polar ecosystems
might react to future climate change.
Researchers have generated many new findings
using a suite of cutting-edge technologies,
with airborne laser altimetry and radar
and an under-ice remotely operated vehicle
the highlights.
Voyage Leader Dr Tony Worby said that for
the first time ever in Antarctica, helicopter
flights covered thousands of kilometres
tracking over the sea ice, gathering large-scale
information about ice and snow conditions
in the region.
"Two helicopters, equipped with laser
and radar altimeters, were used to measure
the height of the snow and ice surfaces
above sea level.
"The helicopter data were complemented
by information gathered from ice coring
and other work directly on the ice. The
combined information will help validate
satellite altimetry data, which will eventually
be used to monitor changes in sea ice thickness
around Antarctica," Dr Worby said.
Sea ice researchers also made the first
measurements of the fluid permeability -
the ability of fluid to flow through channels
in the ice - of the seasonal Antarctic sea
ice pack. With permeability affecting a
range of processes in global climate, polar
biology and oceanography, these initial
data will have important implications.
Biologists combined classical ice coring
techniques with the remotely operated vehicle
(ROV) to study the underside of the sea
ice, to map the distribution of ice algae
– microscopic plants that live in and on
the underside of the ice.
Dr So Kawaguchi, marine ecologist with
the Australian Antarctic Division, said
that the ROV observations showed high concentrations
of Antarctic krill living at the underside
of the sea ice as well as in cracks between
ice floes.
"Using trawls and underwater cameras,
the biology team mapped the distribution
and the condition of the krill.
"Krill found in and around the ice
were in better condition than those found
in areas of open water.
"The krill are feeding on the ice
algae and, in turn, serve as a food source
for penguins, seals and whales.
"An unusual observation was the co-occurrence
of three krill species that generally live
in very different oceanographic regions,"
Dr Kawaguchi said.
Other scientists worked on ice algae physiology
and sea ice biogeochemistry to better understand
processes in the Antarctic sea ice zone
during the transition from winter to summer.
Oceanographers studied the water mass properties
and currents beneath the sea ice and found
that, contrary to what was expected, the
patterns of sea ice drift appear to be affected
more by ocean currents than by wind.
The Sea Ice Physics and Ecosystems Experiment
(SIPEX) is an International Polar Year project.
Throughout the voyage the team posted daily
reports on the voyage web site and blog.
www.acecrc.sipex.aq
Patti Lucas, Public Affairs, Australian
Antarctic Division
+ More
Antarctic air link prepares for take-off
16 October 2007 - Final preparations are
underway for the start of Australia's new
Antarctic air link to support the Australian
Antarctic programme.
The newly painted and modified Airbus A319,
to be used in the Australian Antarctic Division's
air service from Hobart to Antarctica, is
in Hobart this week for ground crew and
pilot training.
Project Manager, Charlton Clark, said it
is important that the ground crew become
familiar working and operating around the
aircraft in Hobart at temperatures around
20ºC, before they do the same work
on ice in Antarctica at -20ºC.
"This week's training is a key element
of our risk management approach to the introduction
of the air service," Mr Clark said.
"The A319 will also undergo further
regulatory checks before the initial flights
commence later this year."
Mr Clark said the air service will modernise
and increase the flexibility of the Australian
Antarctic programme. However, as this is
a new air service into one of the most hostile
environments on earth, weather conditions
will have a major influence on its operation,
as they do on any Antarctic operation.
"While we have scheduled two flights
to transport scientists and expeditioners
south in December, the final schedule for
the months ahead will be driven by the weather,"
Mr Clark said.
The air service from Hobart to an ice runway
near Casey station will operate over summer,
with an estimated 10 to 20 flights per season
to be conducted once the system is fully
operational.
The intercontinental air service will complement
the existing use of ski-equipped C212 aircraft
within Antarctica and, combined with the
shipping service, will improve access to
the frozen continent.
Mr Clark said the team working on the 4000
m Wilkins runway, 70 km south-east of Casey
station, would travel by ship to Antarctica
later this month to finalise preparations
for the service to begin.
In 2005 the Australian Government announced
funding of $46.3m over four years to establish
an air service between Australia and Antarctica.
More details on the Airlink can be found
on the AAD website.
Wendy Pyper
